Joe diGenova, an informal legal adviser to President Trump, unloaded on a host of The Hill TV after she questioned whether Attorney General William Barr is a liar.

The former U.S. attorney for the District of Columbia defended Barr as “one of the finest lawyers this country has ever produced” during a discussion with hosts Buck Sexton and Krystal Ball on Hill.TV Thursday.

Things got heated as Ball pressed the issue of special counsel Robert Mueller basing his decisions in the investigation of alleged collusion in 2016 between the Trump campaign and Russia on whether a sitting president can be indicted. The former MSNBC host hashed it out with guest, Victoria Toensing is a partner with her husband, diGenova, in the Washington law firm diGenova & Toensing.

“I’m asking if Barr is a liar, is really the question,” Ball replied, echoing claims from the left that the attorney general was covering for Trump, with many calling out what they alleged was political “spin” to protect Trump.

“Let me just say something right now about what you just said,” diGenova interjected.

“Don’t you dare suggest that Bill Barr is a liar,” diGenova said. “I’ve known him for 30 years. He’s one of the finest lawyers this country has ever produced. He came back out of retirement to serve this country.”

“There’s not one shred of evidence that anything he said — either the other day, or now, or today — was a lie,” diGenova added. “Don’t ever say that in front of me about Bill Barr. You have no evidence that he lied, and you know it.”

“What I’m telling you is that what he said today is inconsistent with what’s in the report,” Ball replied, defending her comments.

“That’s not a lie!” diGenova fired back as Ball responded, “OK, fine.”

“It’s not fine. You’re on national television calling the attorney general a liar,” diGenova argued, as Ball insisted, “I didn’t say that.”

“You suggested it very strongly,” diGenova shot back.

“Ok, I think we’re done here,” Ball concluded, as her guest agreed.

Speaking with reporters at Thursday’s press conference, Barr indicated that Justice Department officials had asked Mueller “about the OLC opinion and whether or not he was taking the position that he would have found a crime but for the existence of the OLC opinion.”

The Justice Department’s Office of Legal Counsel (OLC) asserts that a sitting president cannot be indicted, something that Mueller’s report apparently suggests could have factored into the investigation of whether Trump obstructed justice.

“He made it very clear, several times, that he was not taking a position — he was not saying but for the OLC opinion he would have found a crime,” Barr said Thursday.

Democrats were up in arms about Barr holding the press conference and, despite his statement that the special counsel’s investigation found “no collusion” between the Trump campaign and Russia in the 2016 election apparently is not final or conclusive enough for the left.

House Speaker Nancy Pelosi and Senate Majority Leader Chuck Schumer issued a statement slamming Barr and his “regrettably partisan handling” of the Mueller report – hours before the attorney general even held a news conference on the impending release of the redacted report.